It comes amid a rise in knife crime around the county, with the number of crimes involving knives in Norfolk tripling since 2013, according to figures from April.

The two men involved in Monday’s incident fled the scene on bicycles. One is described as a white man in his mid 30s, of medium build, around 5ft 6in tall and wearing a black hooded top and beige jogging bottoms.

The other is as a white man in his mid-20s, of slim build, having facial hair and wearing a grey hooded top and black trousers.